Problem: Khan.scratchpad.disable(); Kevin sells magazine subscriptions and earns $$6$ for every new subscriber he signs up. Kevin also earns a $$34$ weekly bonus regardless of how many magazine subscriptions he sells. If Kevin wants to earn at least $$72$ this week, what is the minimum number of subscriptions he needs to sell?
Solution: To solve this, let's set up an expression to show how much money Kevin will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Kevin wants to make at least $$72$ this week, we can turn this into an inequality. Amount earned this week $\geq $72$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $72$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $6 + $34 \geq $72$ $ x \cdot $6 \geq $72 - $34 $ $ x \cdot $6 \geq $38 $ $x \geq \dfrac{38}{6} \approx 6.33$ Since Kevin cannot sell parts of subscriptions, we round $6.33$ up to $7$ Kevin must sell at least 7 subscriptions this week.